Short messaging service (“SMS”) and multimedia messaging service (“MMS”) have become very popular methods of transferring data to and from wireless devices. SMS provides a mechanism for transmitting short alphanumeric messages to and from wireless devices. Currently, alphanumeric messages up to 160 characters can be supported.
A wireless network may provide a short message service center (“SMSC”) which acts as a store and forward system for short messages. The store and forward function provides a method of sending short messages to their destination recipient or storing those messages if the recipient is unavailable to receive them. This store and forward function can generally be distinguished from the real-time delivery requirements of voice calls, although SMS messages may be delivered in real time.
The SMSC can send messages to or from a functional entity known as a short message entity (“SME”). The SME is an entity that can receive or send short messages. The SME is often an application entity that resides on a mobile station. Alternatively, the SME can reside on another entity in a wireless or fixed network. Typically, the SME can be arranged to compose, store, dispose of, act upon, display and/or otherwise manage short messages. The SME may also perform signaling functions to support other delivery features; such as mobile station location and status queries, and mapping of destination addresses.
An SMS message may be sent to a mobile station. In this scenario, the SMS message is referred to as a mobile-terminated short message (“MT-SM”). When a MT-SM message is sent to a mobile station, the SMSC sends an SMS Request to a home location register (“HLR”) to find the mobile station. The HLR provides the mobile station's status, (e.g., whether the station is active or inactive, where the mobile station is located) to the SMSC. If the mobile station is inactive, the SMSC holds the MT-SM message for a period of time. When the mobile station is activated, the HLR sends an SMS Notification to the SMSC. The SMSC then attempts to deliver the MT-SM message to the mobile station.
Additionally, an SMS message may be sent by a mobile station to a terminating device. In this scenario, the SMS message is referred to as a mobile-originated short message (“MO-SM”). Mobile-originated short messages are transported from the mobile station to the SMSC and can be destined for other mobile stations or to subscribers on fixed networks, such as paging networks or electronic mail networks. The network associated with the terminating device pages the terminating device. If the terminating device responds, the MO-SM message is sent to the terminating device and the network notifies the SMSC that the MO-SM message has been sent.
MMS is a means by which multimedia messages can be sent over the air interface to and from wireless devices. Multimedia consists of one or more media elements, such as text, voice, image, and video. A wireless network may provide a multimedia messaging service center (“MMSC”) which stores MMS messages and transmits an MMS notifier to a terminating device. In response to the MMS notifier, the terminating device may give the MMSC permission to deliver the stored MMS message.
Other methods of delivering data messages to and from wireless devices are also known. For example, Sprint customers using Vision cell phones may send pictures with Picture Mail and video with Video Mail. These delivery methods use data messaging standards different from SMS and MMS.